Regeneration method for gravity-flowing deactivated catalyst particles

Abstract

A continuous method for regenerating deactivated catalyst particles in a regeneration zone through which the particles are downwardly movable by way of gravity-flow. Particles are initially introduced into an upper carbon-burning/halogenation section wherein they are contacted by a first air stream and a halogen, or halogen-containing compound. Therefrom, the catalyst particles flow into a lower drying section, wherein they are contacted with a dry second air stream.

We claim as our invention: 
     
       1. A method for continuously regenerating hydrocarbon conversion catalyst particles comprising a Group VIII metal and a halogen component in combination with a refractory inorganic oxide carrier material, and which have become deactivated through use in said hydrocarbon conversion reaction by (1) deposition of carbonaceous matter thereon and through (2) loss of halogen therefrom, said continuous regeneration being effected in a regeneration zone wherein said particles are downwardly movable through a descending column via gravity-flow in countercurrent relationship with the upward flow of vapors within said zone and wherein said regeneration zone comprises a carbon-burning/halogenation first section interconnected with and surmounted with respect to a lower drying second section, which regeneration method comprises the interrelated sequential steps of: (a) introducing (i) deactivated catalyst particles, (ii) a first air stream from an external source and, (iii) a halogen or a halogen-containing compound from an external source into said upper carbon-burning/halogenation first section;   (b) maintaining said catalyst particles within said first section for a time sufficient to (i) remove substantially all of said carbonaceous matter therefrom and, (ii) increase the halogen content thereof;   (c) introducing (i) said catalyst particles from said carbon-burning/halogenation first section, via of said gravity-flow, and, (ii) a second air stream from an external source into said lower drying section, and maintaining said catalyst particles within said lower drying section for a time sufficient to remove substantially all the water therefrom; and   (d) withdrawing substantially water-free, regenerated particles from said regeneration zone.   
     
     
       2. The method of claim 1 further characterized in that said carbon-burning/halogenation section is maintained at a temperature in the range of about 750° F. to about 1050° F. 
     
     
       3. The method of claim 1 further characterized in that said lower drying section is maintained at a temperature of about 830° F. to about 1000° F. 
     
     
       4. The method of claim 1 further characterized in that said first air stream is introduced into said carbon-burning/halogenation section through the same locus through which said halogen, or halogen-containing compound is introduced. 
     
     
       5. The method of claim 1 further characterized in that the mole ratio of the air in said first stream to that in said second stream is at least 1.0:1.0. 
     
     
       6. The method of claim 1 further characterized in that excess air and the combustion products resulting from the burning of carbon, are withdrawn from said carbon-burning section, cooled and at least in part recycled to said carbon-burning and drying sections. 
     
     
       7. The method of claim 6 further characterized in that said excess air and combustion products are recycled to said carbon-burning and drying sections without intermediate treatment.